I loved PoE and every little bit about the world but I never really caught what the name of the game reffers to.

 

Maybe I just missed it on my way through the piles of dead bodies.

 

"Pillars" ...of "Eternity"?

I could be dead wrong, but my guess is it refers to the adra pillars, which can store souls.

I think its adra pillars or maybe more in metaphor the Wheel of Berath.

Yeah I was thinking around those lines too tbh but the game never really elaborates 100% clearly in any lore book or dialogue Ive seen atleast.

It is the adra pillars... I mean look at the game box... It says Pillars of Eternity... with Adra stones behind the words lol. 

I assumed it was a reference to the adra prison

My guess is the adra pillars. There is one on the opening screen when the title shows and the lore says souls use these pillars as conduits to the underworld i think.

There are actual pillars in Breith Eaman